1. Field
The present disclosure relates to systems using electric motors, more specifically to AC electric motors used in a vehicle.
2. Description of Related Art
Rocket propelled vehicles can include fuel and oxidizer pumps that are mechanically linked to a power generation turbine which is powered by exhaust gas from a separate combustion chamber not associated with the main rocket engine combustor. The pumps can be mechanically connected to the power generation turbine via a gear train. In this case, the speed of each pump is proportional to the speed of the power generation turbine which is variable, thus the speed of each pump is controlled by changing the rotational speed of the power generation turbine. With this type of mechanical power transmission architecture, the rotational speed of the pumps cannot be independently controlled. Moreover, the mechanical system that links the pumps to the power generation turbine is heavy and requires the pumps to be located near the power generation turbine. In some situations, the oxidizer pump and the fuel pump can be mounted on the same rotating shaft as the power generation turbine. This architecture does not have the complexity of the geared rocket turbo-pump architecture described above, however, the efficiency of the pumps and the power generation turbine are reduced, since each component is forced to operate at the same rotational speed.
It would be possible to power electrically driven AC powered pumps with an AC-DC-AC conversion system that is configured to control the speed of each pump independently of the speed of the power generation turbine, however, such a system would add substantial weight to the rocket propelled vehicle and would not necessarily be beneficial over a mechanical system.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for a system that allows for the efficient use of electric motor pumps in a rocket propelled vehicle. The present disclosure provides a solution for this problem.